Topic 6.4: Gas Exchange

Question 1

What is the purpose of ventilation?

Answer 1

Ventilation maintains concentration gradients of oxygen and carbon dioxide between air in alveoli and blood flowing in adjacent capillaries

Question 2

Define ventilation

Answer 2

Ventilation: The exchange of air between the atmosphere and the lungs – achieved by the physical act of breathing

Question 3

Define gas echange

Answer 3

Gas Exchange: The exchange of oxygen and carbon dioxide between the alveoli and bloodstream (via passive diffusion)

Question 4

Define physiological respiration

Answer 4

Physiological respiration involves the transport of oxygen to cells within the tissues, where energy production occurs

Question 5

How is air carried throughout the body?

Answer 5

Air is carried to the lungs in the trachea and bronchi and then to the alveoli in bronchioles

Question 6

Define pneumocytes

Answer 6

Pneumocytes (or alveolar cells) are the cells that line the alveoli and comprise of the majority of the inner surface of the lungs

Question 7

What is the purpose of type I pneumocytes?

Answer 7

Type I pneumocytes are involved in the process of gas exchange between the alveoli and the capillaries

Question 8

What is the purpose of type II pneumocytes?

Answer 8

Type II pneumocytes are responsible for the secretion of pulmonary surfactant, which reduces surface tension in the alveoli

Question 9

What happens when the pressure in the chest is less than the atmospheric pressure?

Answer 9

When the pressure in the chest is less than the atmospheric pressure, air will move into the lungs (inspiration)

Question 10

What happens when the pressure in the chest is greater than the atmospheric pressure?

Answer 10

When the pressure in the chest is greater than the atmospheric pressure, air will move out of the lungs (expiration)

Question 11

What cause the pressure changes inside the thorax that forces air in and out of the lungs?

Answer 11

muscle contractions

Question 12

What are the two muscles responsible for inspiration?

Answer 12

The muscles responsible for inspiration are the diaphragm and external intercostals (plus some accessory muscles)

Question 13

What are the two muscles responsible for expiration?

Answer 13

The muscles responsible for expiration are the abdominal muscles and internal intercostals (plus some accessory muscles)

Question 14

Define spirometry

Answer 14

Spirometry involves measuring the amount (volume) and / or speed (flow) at which air can be inhaled or exhaled

Question 15

Define spirometer

Answer 15

A spirometer is a device that detects the changes in ventilation and presents the data on a digital display